Aggregation Commands


For details on specific commands, including syntax and examples, click on the specific command to go to its reference page.

Name Description
aggregate Performs aggregation tasks such as $group using an aggregation pipeline.
count Counts the number of documents in a collection or a view.
distinct Displays the distinct values found for a specified key in a collection or a view.
mapReduce Performs map-reduce aggregation for large data sets.

For a detailed comparison of the different approaches, see Aggregation Commands Comparison.